• Title, Summary, Keyword: cDNA Microarray

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Evaluation of Amplified-based Target Preparation Strategies for Toxicogenomics Study : cDNA versus cRNA

  • Nam, Suk-Woo;Lee, Jung-Young
    • Molecular & Cellular Toxicology
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    • v.1 no.2
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    • pp.92-98
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    • 2005
  • DNA microarray analysis of gene expression in toxicogenomics typically requires relatively large amounts of total RNA. This limits the use of DNA microarray when the sample available is small. To confront this limitation, different methods of linear RNA amplification that generate antisense RNA (aRNA) have been optimized for microarray use. The target preparation strategy using amplified RNA in DNA microarray protocol can be divided into direct-incorporation labeling which resulted in cDNA targets (Cy-dye labeled cDNA from aRNA) and indirect-labeling which resulted in cRNA targets (i.e. Cy-dye labeled aRNA), respectively. However, despite the common use of amplified targets (cDNA or cRNA) from aRNAs, no systemic assessment for the use of amplified targets and bias in terms of hybridization performance has been reported. In this investigation, we have compared the hybridization performance of cRNA targets with cDNA targets from aRNA on a 10 K cDNA microarrays. Under optimized hybridization conditions, we found that 43% of outliers from cDNA technique and 86% from the outlier genes were reproducibly detected by both targets hybridization onto cDNA microarray. This suggests that the cRNA labeling method may have a reduced capacity for detecting the differential gene expression when compared to the cDNA target preparation. However, further validation of this discordant result should be pursued to determine which techniques possesses better accuracy in identifying truly differential genes.

Balanced Experimental Designs for cDNA Microarray data

  • Choi, Kuey-Chung
    • 한국데이터정보과학회:학술대회논문집
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    • pp.121-129
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    • 2006
  • Two color or cDNA microarrays are extensively used to study relative expression levels of thousands of genes simultaneously. 0かy two tissue samples can be hybridized on a single microarray slide. Thus, a microarray slide necessarily forms an incomplete block design with block size two when more than two tissue samples are under study. We also need to control for variability in gene expression values due to the two dyes. Thus, red and green dyes form the second blocking factor in addition to slides. General design problem for these microarray experiments is discussed in this paper. Designs for factorial cDNA microarrays are also discussed.

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Genes expression monitoring using cDNA microarray: Protocol and Application

  • Muramatsu Masa-aki
    • Proceedings of the Korean Society of Toxicology Conference
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    • pp.31-41
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    • 2000
  • The major issue in the post genome sequencing era is determination of gene expression patterns in variety of biological systems. A microarray system is a powerful technology for analyzing the expression profile of thousands of genes at one experiment. In this study, we constructed cDNA microarray which carries 2,304 cDNAS derived from oligo-capped mouse cDNA library. Using this hand-made microarray we determined gene expression in various biological systems. To determine tissue specific genes, we compared Nine genes were highly-expressed in adult mouse brain compared to kidney, liver, and skeletal muscle. Tissue distribution analysis using DNA microarray extracted 9 genes that were predominantly expressed in the brain. A database search showed that five of the 9 genes, MBP, SC1, HiAT3, S100 protein-beta, and SNAP25, were previously known to be expressed at high level in the brain and in the nervous system. One gene was highly sequence similar to rat S-Rex-s/human NSP-C, suggesting that the gene is a mouse homologue. The remaining three genes did not match to known genes in the GenBank/EMBL database, indicating that these are novel genes highly-expressed in the brain. Our DNA microarray was also used to detect differentiation specific genes, hormone dependent genes, and transcription-factor-induced genes. We conclude that DNA microarray is an excellent tool for identifying differentially expressed genes.

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Development of a Reproducibility Index for cDNA Microarray Experiments

  • Kim, Byung-Soo;Rha, Sun-Young
    • Proceedings of the Korean Statistical Society Conference
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    • pp.79-83
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    • 2002
  • Since its introduction in 1995 by Schena et al. cDNA microarrays have been established as a potential tool for high-throughput analysis which allows the global monitoring of expression levels for thousands of genes simultaneously. One of the characteristics of the cDNA microarray data is that there is inherent noise even after the removal of systematic effects in the experiment. Therefore, replication is crucial to the microarray experiment. The assessment of reproducibility among replicates, however, has drawn little attention. Reproducibility may be assessed with several different endpoints along the process of data reduction of the microarray data. We define the reproducibility to be the degree with which replicate arrays duplicate each other. The aim of this note is to develop a novel measure of reproducibility among replicates in the cDNA microarray experiment based on the unprocessed data. Suppose we have p genes and n replicates in a microarray experiment. We first develop a measure of reproducibility between two replicates and generalize this concept for a measure of reproducibility of one replicate against the remaining n-1 replicates. We used the rank of the outcome variable and employed the concept of a measure of tracking in the blood pressure literature. We applied the reproducibility measure to two sets of microarray experiments in which one experiment was performed in a more homogeneous environment, resulting in validation of this novel method. The operational interpretation of this measure is clearer than Pearson's correlation coefficient which might be used as a crude measure of reproducibility of two replicates.

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Comparison of Hybridization Behavior between Double and Single Strand of Targets and the Application of Asymmetric PCR Targets in cDNA Microarray

  • Wei, Qing;Liu, Sanzhen;Huang, Jianfeng;Mao, Xueying;Chu, Xiaohui;Wang, Yu;Qiu, Minyan;Mao, Yumin;Xie, Yi;Li, Yao
    • BMB Reports
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    • v.37 no.4
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    • pp.439-444
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    • 2004
  • Double stranded targets on the cDNA microarray contain representatives of both the coding and noncoding strands, which will introduce hybridization competition with probes. Here, the effect of double and single strands of targets on the signal intensity and the ratios of Cy5/Cy3 within the same slide were compared. The results show that single stranded targets can increase the hybridization efficiency without changing the Cy5/Cy3 ratio. Based on these results, a new strategy was established by generating cDNA targets with asymmetric PCR, instead of conventional PCR, to increase the sensitivity of the cDNA microarray. Furthermore, the feasibility of this approach was validated. The results indicate that the cDNA microarray system based on asymmetric PCR is more sensitive, with no decrease in the reliability and reproducibility as compared with that based on conventional symmetric PCR.

Toxicogenomic analysis of Effects of Bisphenol A on Japanese Medaka fish using high density-functional cDNA microarray

  • Jiho Min;Park, Kyeong-Seo;Hong, Han-Na;Gu, Man-Bock
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • pp.173-173
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    • 2003
  • With the introduction of DNA microarrays, a high throughput analysis of gene expression is now possible as a replacement to the traditional time-consuming Southern-blot analysis. This cDNA microarray should be ahighly favored technology in the area of molecular toxicology or analysis of environmental stresses.In this study, therefore, we developed a novel cDNA microarray for analyzing stress-specific responses in japanese Medaka fish. In the design and fabrication of this stress specific functional cDNA microarray, 123 different genes in Medaka fish were selected from eighteen different stress responsive groups and spotted on a 25${\times}$75 mm glass surface. After exposure of the fish to bisphenol A which is the one of the well-known endocrine disrupting chemicals (EDCs), over 1 or 10 days, the responses of the DNA chip were found to show distinct expression patterns according to the mode of toxic actions from environmental toxicants. As a results, they showed specific gene expression pattern to bisphenol A, additionally, the chemical spesific biomarkers could be suggested based on the chip analysis data. Therefore, this chip can be used to monitor stress responses of unknown and/or known toxic chemicals using Medaka fish and may be used for the further development of biomarkers by utilizing the gene expression patterns for known contaminants.

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cDNA microarray profiling of Bombyx mori(kl20) during early embryogenesis

  • Hong, Sun-Mee;Kang, Seok-Woo;O, Tae-Jaeng;Kim, Nam-Soon;Lee, Jin-Sung;Goo, Tae-Won;Yun, Eun-Young;Choi, Ho;Hwang, Jae-Sam;Nho, Si-Kab
    • Proceedings of the Korean Society of Sericultural Science Conference
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    • pp.47-48
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    • 2003
  • The development of cDNA microarray has permitted the analysis of thousands of genes simultaneously. cDNA microarray has been used to analyze gene expression profiles during developmental stage in both single and multicellular organisms. Two significant factors contributing to the limitation of the development of cDNA microarray in the Bombyx mori are the shortage of accessible repositories of cDNA clones and ESTs and the relative scarcity of facilities to produce microarrays and analyze the data generated. (omitted)

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cDNA Microarray in Psychiatry (정신의학에서의 cDNA Microarray)

  • Yang, Byung-Hwan;Kim, Ja-Yoon
    • Korean Journal of Biological Psychiatry
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    • v.7 no.2
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    • pp.123-130
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    • 2000
  • The development of inexpensive high throughput methods to identify individual DNA sequences is important to the future growth of medical genetics. This has become increasingly apparent as psychiatric geneticists focus more attention on the molecular basis of complex multifactorial diseases at which most of psychiatric disease is estimated. Furthermore, candidate gene approaches used in identifying disease associated genes necessitate screening large sequence blocks for changes tracking with the disease state. Even after such genes are isolated, large scale mutational analysis will often be needed for risk assessment studies to define the likely medical consequences of carrying a mutated gene. This review provide basic knowledge of up-to-date technology, cDNA microarray which enables above mentioned various research themes.

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Construction of Ovine Customer cDNA Chip and Analysis of Gene Expression Patterns in the Muscle and Fat Tissues of Native Korean Cattle (cDNA microarray를 이용하여 한우의 근육과 지방조직의 유전자 발현 패턴 분석 및 bovine customer cDNA chip 구성 연구)

  • Han, Kyung Ho;Choi, Eun Young;Hong, Yeon-Hee;Kim, Jae Yeong;Choi, In Soon;Lee, Sang-Suk;Choi, Yun Jaie;Cho, Kwang Keun
    • Journal of Life Science
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    • v.25 no.4
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    • pp.376-384
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    • 2015
  • To investigate the molecular events of controlling intramuscular fat (or marbling), which is an important factor in the evaluation of beef quality, we performed cDNA microarray analyses using the longissimus dorsi muscle and back fat tissues. For this study, we constructed normalized cDNA libraries: fat tissues in native Korean cattle (displaying 1,211 specific genes), and muscle tissues in native Korean cattle (displaying 1,346 specific genes). A bovine cDNA chip was constructed with 1,680 specific genes, consisting of 760 genes from muscle tissues and 920 genes from fat tissues. The microarray analysis in this experiment showed a number of differentially expressed genes, which compared the longissimus dorsi muscle (Cy5) with back fat tissue (Cy3). Among many specific differentially expressed genes, 12-lipoxygenase (oxidizing esterified fatty acids) and prostaglandin D synthase (differentiation of fibroblasts to adipocytes) are the key candidate enzymes that should be involved in controlling the accumulation of intramuscular fat. In this study, differentially and commonly expressed genes in the muscle and fat tissues of native Korean cattle were found in large numbers, using the hybridization assay. The expression levels of the selected genes were confirmed by semi-quantitative RT-PCR, and the results were similar to those of the cDNA microarray.

Analysis of X Irradiation Related Genes in HL60 Cells Using cDNA Microarray (cDNA Microarray를 이용한 HL60 세포주에서 방사선 조사 관련 유전자의 검색 및 분석)

  • Park, Keon-Uk;Hwang, Mi-Sun;Suh, Seong-Il;Suh, Min-Ho;Kwon, Taeg-Kyu;Park, Jong-Wook;Cho, Jae-We;Choi, Eun-Ju;Baek, Won-Ki
    • The Journal of the Korean Society for Microbiology
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    • v.35 no.4
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    • pp.299-308
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    • 2000
  • Recently developed cDNA microarray or DNA chip technology allows expression monitoring of expression of hundreds and thousands of genes simultaneously and provides a format for identifying genes as well as changes in their activity. In order to search for changes in gene expression after X irradiation in HL60 cells, cDNA microarray technique was done. In this study, expression of 588 human genes (including oncogenes, tumor suppressor genes, cell cycle regulator genes, intracellular signal transduction modulator genes, apoptosis related genes, transcription factor genes, growth factors and receptor genes, cytokine genes, etc) were analyzed. For cDNA microarray analysis mRNAs were extracted from control and 8 Gy-irradiated HL60 cells. As a result the changes in expression of several genes were observed. This alteration of gene expression was confirmed by reverse transcription-polymerase chain reaction. The expression of heat shock 60 KD protein, c-jun, erythroid differentiation factor, CPP32, myeloid cell nuclear differentiation antigen, MAP kinase-activated protein kinase, interleukin-8, monocyte chemotactic peptide 1 and RANTES genes was increased, but the expression of p55CDC gene was decreased after X irradiation.

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